Comparative study of semi-quantitative analysis on dual energy lung perfusion imaging in acute pulmonary embolism before and after treatment / 实用放射学杂志

ABSTRACT

Objective To investigate the application of semi-quantitative analysis of dual energy lung perfusion imaging(DEPI)in patients with acute pulmonary embolism(PE)before and after treatment.Methods 25 patients with acute PE diagnosed by dual source CT were recruited consecutively.All of them underwent CT pulmonary angiography(CTPA)and DEPI before and after treatment. Radiologists visually evaluated the PE numbers,its distribution(central or peripheral)and its nature(occlusive or non-occlusive)on CTPA.DEPI visual analysis and semi-quantitative analysis before and after treatment in different types of PE evaluated by CTPA were analyzed statistically.Results Four types of PE(central occlusive PE,central non-occlusive PE,peripheral occlusive PE and peripheral non-occlusive PE)were classified according to embolic sites and the extent of embolization.Comparing to CTPA as a standard reference,the positive rates of DEPI visual analysis were 100.00%,70.54%,87.23%,76.19% before treatment,100.00%, 76.67%,86.67%,77.78% after treatment,respectively.Significant differences were found in central occlusive PE,central non-occlusive PE and peripheral occlusive PE with mean difference of CT values before and after treatment[(70.7 ± 10.1)HU vs(29.8 ± 6.0)HU,P<0.01;(50.1 ± 9.6)HU vs(29.3 ± 7.8)HU,P< 0.01;(53.4 ± 11.4)HU vs(27.4 ± 8.9)HU,P<0.01,respectively].Although(24.5 ± 8.2)HU (after treatment)were lower than(28.5 ± 9.0)HU(before treatment),no significant difference was found in the type of peripheral non-occlusive PE(P> 0.05).Conclusion The combination of CTPA and DEPI can offer more comprehensive information of the acute PE therapeutic evaluation before and after treatment.